Multi-conductor cable connector of bridging type



y 30, 1967 A. I. APPLETON 3,32

MULTI-CONDUCTOR CABLE CONNECTOR OF BRIDGING TYPE Fi led June 9, 1964 3 Sheets-Sheet l mmmmm mmmmm v gm a IHIHHIIHIHM lllllllllllllllll MJQYEXJ3T- May 30, 1967 A. APPLETON 3,323,096

MULTI-GONDUCTOR CABLE CONNECTOR OF BRIDGING TYPE Filed June 9, 1964 3 Sheets-Sheet 2 INVENTOR ARTHUR [,APPLETON a m w, aw

A. l. APPLETON 3,323,096

5 Sheets-$heet 3 MULTI-GONDUCTOR CABLE CONNECTOR OF BRIDGING TYPE ENVE N 'mfl Ara WM 2. A mermv at]: 7 7 $67M ATTYS:

May 30, 1967 Filed June 9, 1964 L /Illa 0m MN w \.u

United States Patent The present invention relates in general to the field of electrical connectors and, more specifically, to a novel connector which finds particular, but not exclusive, utility for making detachable connections in multi-conducto-r power or control cable.

One object of the invention is to provide an electrical connector of compact form having positive and reliable means for connecting the contacts thereof and which will readily lend itself to mass productive manufacture over a particularly wide range of capacities and sizes.

Another object of the invention is to provide a connector of simple, rugged construction which will be substantially less susceptible of damage in the course of ordinary handling and usage than connectors of the types heretofore known.

A further object is to provide a connector of the character set forth and which will be susceptible of ready replacement of the wearable elements without necessity for breaking or reconnecting the permanent electrical connections with the various conductors of the cable. Another object of the invention is to provide a connector of the foregoing nature and which will include a built-in fuse arrangement for overload or short-circuit protection.

Still another object is to provide an electrical connector capable of flexible operation with multi-conductor cable permitting ready shifting of use from one set of wires to a spare set Within the same cable.

A further object is to provide a contact assembly for an electrical connector of the character set forth and which will be susceptible of quick, positive attachment to a conductor without soldering or crimping.

Other objects and advantages will become apparent as the following description proceeds, taken together with the accompanying drawings wherein:

FIGURE 1 is a longitudinal sectional view, partially in elevation, showing the two major members of an illustrative connector embodying the present invention prior to assembly thereof.

FIG. 2 is a longitudinal sectional view of the illustrative connector of FIG. 1 but with the two major members thereof interfitted together.

FIG. 3 is an exploded vertical sectional View of the bridge assembly of the connector of FIGS. 1 and 2.

FIG. 4 is an end elevational view of one of the components of the bridge assembly of FIG. 3, taken in the plane of the line 44 of FIG. 3.

FIG. 5 is a longitudinal sectional view through the connector bridge assembly with the parts thereof in place.

FIGS. 6 and 7 are end elevational views of the bridge assembly of FIG. 5.

FIG. 8 is a fragmentary transverse sectional view through a portion of the bridge assembly, taken in the plane of the line 8-8 in FIG. 1.

FIG. 9 is a fragmentary vertical sectional view through the bridge assembly of FIG. 5 and showing the manner in which a male contact engages the associated bridge element therein.

FIG. 10 is an enlarged fragmentary longitudinal sectional view detailing the relation between a pair of opposed mating contacts and the bridge assembly in the connector of FIG. 1.

FIGS. 11, 12 and 13 are enlarged detail views of the stripped conductor and contact elements utilized in illustrative connector of FIG. 1.

FIG. 14 is a side elevational view showing an assembled contact element of the connector.

FIG. 15 is a fragmentary vertical sectional view through a bridge assembly somewhat similar to that of FIG. 5 but slightly modified internally.

FIGS. 16 and 17 are longitudinal sectional views illustrating a further modification of the invention embodied in another exemplary connector.

FIGS. 18 and 19 are fragmentary vertical sectional views through two bridge assemblies similar to that of FIG. 5 but each including further modified bridge elements.

While the invention is susceptible of various modifications and alternative constructions, certain illustrative embodiments have been shown in the drawings and will be described below in considerable detail. It should be understood, however, that there is no intention to limit the invention to the specific forms or modes disclosed, but, on the contrary, the intention is to cover all modifications, alternatives and equivalents falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more specifically to FIGURES 1 and 2, the invention is there exemplified in an illustrative connector 20 adapted to connect corresponding opposed pairs of electrical conductors 21, 22 together. It will be appreciated that the conductors 21, 22 may be included in multiconnector cable, or may simply be individually run wires, and that they may be utilized in power, control, or communication circuitry. The connector 20 comprises a pair of interiitting major members of tubular form which in this case happen to be a plug 24 and a receptacle 25. The plug 24 comprises a tubular body 26 and a retainer nut 28 which engages an external flange 29 on the plug body. An extension sleeve 30 is thfeadedly attached to the outer end of the plug body and in this instance is provided with a sealing bushing 31 and sealing nut 32 for engaging the sheath of a connected cable (not shown). The receptacle 25, on the other hand, comprises a tubular body 34 and an external mounting flange 35 which may have a sealing gasket 36 associated therewith. The receptacle body 34 is adapted to receive telescopically the inner end portion of the plug body 26 when the connector is assembled and is provided with external threads 37 engageable by the plug retainer nut 23. For the purpose of orienting the plug with respect to the receptacle, suitable polarizing means may be provided such, for example, as one or more upstanding ribs 38 on the plug body which engage corresponding grooves 39 in the main bore of the receptacle body.

The connector 20 includes two sets of opposed male contacts 40, one in the plug and the other in the receptacle. To simplify illustration, FIGS. 1, 2 and 10 show a cooperating pair of the contacts 40, one from each set, along with their respectively associated conductors 21, 22. Since the contacts and holding means are substantially identical in both the plug and receptacle, a detailed de scription of such arrangement in one will sufiice for both.

Referring, for example, to the plug 24, it will be noted that the contacts 40 of the latter are compactly nested in a contact holder 41 of non-conductive material (FIGS. 1, 2 and 10). In this instance, the holder 41 comprises a pair of disks 42, 44 of rigid non-conductive material with a disk 45 of resilient non-conductive material such as silicone rubber sandwiched therebetween. Each contact 40 may be retained against rearward pull-out as by means of medially located spring clips 46 which engage an internal shoulder 48 in the disk 42 in a manner known in the art. The contact holder 41 and its contacts may be oriented with respect to the plug 24 by suitable polarizing means, such as longitudinal rib 49 in the interior of the plug body and corresponding common groove 50 in the outer peripheries of the holder elements 42, 44 and 45 (FIGS. 1, 2 and The contact holder 41 is seated against a stop shoulder 51 in the plug body and retained in place as by means of a Washer 52 interposed between the outer end of the plug body and the shoulder 54- adjacent the inner end of the plug extension sleeve 30.

The contacts and holding means in the receptacle 25, as already indicated, are similar to those associated With the plug 24 and further detailed description is not neces sary at this point. Suffice it to say that, in this instance, contact holder 41 is seated in the receptacle body against stop shoulder 55 and secured in place as by means of a washer 56 carried by a retainer nut 58 on the end of the receptacle remote from the plug. The contact holder and receptacle body also include polarizing means such as rib 49 and groove 50 similar to those associated with the plug.

In accordance with an important aspect of the invention, provision is made in the connector for effecting a positive bridging connection between each pair of opposed contacts respectively associated with the plug and receptacle as an incident to assembling the plug and receptacle together. This is accomplished by the use of a resilient bridge element 59 of Phosphor bronze or other resilient conductive material captive-mounted in a nonconductive holder 60 interposed between the opposed contacts 40 and contact holders 41 of the plug and receptacle. Referring more particularly to FIGS. 1 to 5, inclusive, 8 to 10, inclusive, it will be noted that each resilient bridge element 59 in the present instance happens to be fashioned as a leaf spring with a relatively straight central portion and a V-shaped bend adjacent each end. The bridge element 59 and its confining cavity are so proportioned that entry of a contact 40 will cam the element 59 laterally, deforming the same and at the same time setting up wiping contact wtih the contact element 40 under substantial pressure. The bridge holder 60 and captive-bridge elements confined theerin together constitute a bridge assembly.

In the form illustrated herein (FIGS. 3-8), the bridge holder 60 comprises a pair of non-conductive disk members 61, 62 assembled together as by means of a centrally located hollow rivet 64. The outer end of each disk member 61, 62, in other words each end face of the bridge holder 60, is formed with a pattern of holes A, B, C and D adapted to register with and receive corresponding pairs of contacts of the plug and receptacle. The holder 60 also has exterior polarizing means such as longitudinal slot 65 adapted for engagement with aligned longitudinal ribs 66 in the bodies of the plug and receptacle. Internally, each of the members 61, 62 is formed with a plurality of generally circular cavities 68 each having a relatively fiat outer wall portion or pad 67. Each cavity 68 also has a relatively fiat ledge 69 at one end. The disk member 61, 62 are assembled so that their cavities 68 register with each other, each pair of cavities receiving a bridge element 59. As indicated in FIGS. 5 and 9, each bridge element 59 is captive-mounted in a pair of aligned cavities 68 with the apexes of its V-shaped end portions resting on the ledges 69 and its flat central portion in close proximity with the flat pad 67 in the outer wall of the cavities. Each pair of the holes A, B, C and D communicates with a respective pair of the cavities 68. The ledges 69 are so located in relation to the associated pairs of holes A, B, C, D as to be approximately coplanar with the hole diameter. Each hole thus continues across its associated ledge 69 as a semi-circular groove. Consequently, as indicated in FIGS. 8 and 9, entry of a contact 40 into the bridge holder via one of the holes A, B, C, D will result in positive wiping engagement between the contact 40 and the V-shaped portion of the bridge element 59 resting on the ledge 69. Since this is accompanied by deformation of the resilient bridge element which is confined between the contacts 40 and the pads 67 in the outer wall of the cavities 68, the wiping engagement or contact occurs under substantial pressure.

In keeping with another aspect of the invention, provision is made in the connector 20 for securing the bridge assembly to one of the major members of the connector. This is preferably the electrically live or hot member and in the illustrative connector 20 happens to be the receptacle (FIGS. 1 and 2). Attachment of the bridge as sembly, as will be noted from the drawing, safely protects the live contacts 40 from exposure. The foregoing is accomplished as by means of a mounting screw 70 which fits telescopically within the hollow center of the bridge holder 60 and engages an appropriate tapped hole 71 in a plug 72 situated in the face of the receptacle contact holder 41. A similar tapped hole and plug are provided in the face of the plug contact holder 41 and the bridge assembly may be secured to the plug by simply reversing the screw 70.

By reason of this arrangement, it will be appreciated that the parts most likely to wear out are confined within a readily removable member. Thus, if the bridging elements do become worn with substantial usage, the connector may be readily repaired by substituting a new bridge assembly for the old one. This can be done almost instantaneously and without necessity for breaking or otherwise disturbing any of the permanent electrical connections between the contacts 40 and their corresponding conductors 21, 22.

The construction just described also possesses a further advantage in connection with multi-conductor cable. It may, for example, be feasible to use only a portion of the conductors in a multi-conductor cable, the remaining conductors being spares, In such instances, the bridge assembly may be constructed with the bridge elements arranged to connect only the contacts of the conductors in actual use. In event of a failure of one or more of the conductors in use, a bridge assembly with a different arrangement of bridge elements could be quickly substituted for the old bridge assembly and the spare conductors of the cable immediately placed into use.

Another advantage of the foregoing construction is that it makes it possible to utilize a single basis connector, except for the bridge assembly, for a wide variety of electrical ratings. The same connector is readily susceptible of conversion to different ratings simply by substitution of an appropriately rated bridge assembly.

It will be appreciated by those skilled in the art that the resilient bridge elements 59 may be fashioned in a variety of forms. As shown and described earlier herein, the illustrative elements 59 happen to be formed of flat leaf spring stock of Phosphor bronze or other resilient conductive material. By the same token, these parts may be formed of resilient stock of arcuate or semi-circular crosssection. They may also be fashioned as coil springs having a diameter somewhat less than the full diameter of the projecting portions of the contacts 40.

In situations where additional contact area and pressure are desired, the resilient bridge elements 59 may be used in opposed pairs as indicated in FIG. 15. In that event, the ledges 69 would be eliminated from the interior of the disk members 61, 62 and the apexes of the springs would bear against each other until the insertion of the contacts 40. Thereupon, the apexes of the elements 59 would all bear against the contacts it).

In accordance with a further aspect of the invention, provision is made for effecting an eflicient electrical and mechanical connection between each contact and its associated conductor Without the necessity for soldering or crimping. This connection may be made quickly and economically, and with equal facility in the field as Well as in the factory. Referring more particularly to FIGS. 12, 13 and 14, it will be noted that each contact 40 is an assembly comprising two members telescoped together with a relatively close press fit. These members are an inner sleeve 74 and an outer cap 75.

The sleeve 74 is formed with an axial bore 76 adapted to slidably receive the stripped end portion 21A of the conductor 21 (FIGS. 11 and 12). The conductor-receiving end portion of the bore 76 may be relieved or flared outwardly in a bell mouth 76A in order to facilitate entry of the stripped conductor end 21A and to minimize chances of conductor breakage. Intermediate its ends, the sleeve 74 has a flange 78 which defines an abutting shoulder 79. That portion of the sleeve 74 between the flange 78 and its end remote from bell mouth 76A is formed with one or more longitudinal slots 80. As illustrated herein, the sleeve 74 has two slots 80 diametrically opposed and which define a pair of jaws 81 adapted to bear against the stripped end portion 21A of the conductor.

The outer cap 75 is of stepped tubular form and comprises a contact element 84 and an enlarged tubular portion 85. The latter carries intermediate its ends a peripheral spring retainer clip 46, mentioned earlier herein. The end of the cap opposite the contact elements 84 constitutes an abutting shoulder 86. The cap has an axial bore 88 with a length slightly greater than the distance between the abutting shoulder 79 and the slotted end of the sleeve 74. Communicating with the end of the bore 88 adjacent the contact element 84 is a transversely disposed inspection aperture 87. The diameter of the bore 88 is such as to make a relatively snug press fit when telescoped over the slotted end portion of the sleeve 74. To facilitate entry of the latter into the bore 88, the outer end portion of the sleeve may be tapered slightly as at 89.

With the foregoing construction, it will be appreciated that the contact assembly 40 may be readily attached to the stripped end 21A of the conductor by sliding the latter into the bore 76 of the sleeve 74 until the stripped end 21A begins to project from the slotted end of the sleeve 74. The cap 75 is then started over the tapered end 89 of the sleeve 74 and pressed onto the slotted portion of the sleeve by means of an appropriate compression tool. When the abutting shoulder 86 of the cap has been pressed against the stop shoulder 79 of the flange 78, the connection is complete. This may readily be confirmed by the appearance of the stripped end portion of the conductor 21A in the inspection aperture 87 (FIG.

Turning now to FIGS. 16 and 17, another modified form of the invention is there shown embodied in an exemplary connector 90 generally similar to the connector 20 except for the construction of the bridge assembly. In accordance with this aspect of the invention, provision is made for forcing the bridge elements 59 into positive electrical contact with their associated connector contacts 40 as an incident to securing the two major elements of the connector together. Such action may involve establishing electrical contact between these parts or increasing the contact pressure between them which might occur in the absence of this feature. In view of the fact that the differences in this modification reside primarily in the bridge assembly, it will be appropriate to focus upon the latter and to use like reference numerals for common parts described earlier herein.

As shown more particularly in FIGS. 16 and 17, the connector 90 has a bridge holder 91 comprising disk members 94, 95 of non-conductive material having a common central bore. The disk members 94, 95 are held together as by means of hollow rivet 96 which is slidably mounted in the central bore and proportioned to permit limited axial movement between the disk members. The rivet 96 may include appropriate splines to preclude relative rotation between the disk members. The members 94, 95 may be biased into axially spaced position, shown in FIG. 16, as by means of coil spring 98 housed within central recesses around the rivet 96. Such axial biasing may also be by the resilient bridge elements 59 housed in recesses within the disk members after the manner described in connection with disk members 61, 62 of the connector 20. The bridge assembly, comprising the bridge holder 91, and bridge elements 59 may be secured to either the plug 24 or the receptacle 25, in this instance the former, as by means of mounting screw 70.

With the construction just described, upon insertion of the connector plug 24 into the receptacle 25 and tightening of the retainer nut 28 on receptacle threads 37, the disk members 94, of the bridge assembly are compressed axially and brought into abutment with each other as indicated in FIG. 17. This axial compression also results in engagement between the ends of the resilient bridge elements 59 and the respective end walls 99 of their cavities in the disk members. Such axial compression thus deflects the resilient bridge elements 59 against the outer walls of their cavities in the disk members and forces the bridge elements 59 into positive electrical contact with their associated contacts 41]. By regulating the extent of axial movement of the disk members 94, 95, the proportions and resiliency of the bridge elements 59, and the extent of threaded engagement of the retainer nut 28 with the receptacle, the contact pressure between the elements 59 and the contacts 40 may be held at any preselected value. Moreover, when the retainer nut 28 has been brought into its tightened position, the contact pressure reaches a uniform amount which remains substantially constant over the life of the bridge assembly. Alternatively, provision may be made for adjustably vary ing the contact pressure in a given connector and bridge assembly by varying the threaded engagement of the retainer nut 28 on the receptacle and allowing axial clearance between the disk members 94, 95 even when the nut is fully tightened.

For the purpose of enhancing the extent of wiping contact between the resilient bridge elements and their respective associated contacts 48 in the connectors 20 and 98, resort may be had to a further modification of the bridge elements. Referring more specifically to FIG. 18, it will be noted that the bridge assembly may include resilient bridge elements formed with double offset end portions 101 rather than single offset end portions. This gives each end portion the shape of a W, providing two areas of wiping contact at each end of the bridge element 108 and its associated contact 4!).

In accordance with still another aspect of the invention the connector 29 or 90 may include a built-in fuse arrangement for overload or short circuit protection. In this instance, such feature is incorporated into the bridge holder 60 or 91. Accordingly, the latter may include resilient bridge elements 102, illustrated in FIG. 19. Each bridge element 102 has interposed between its ends a fuse element 184. In the present instance, where the resilient bridge element happens to be of Phosphor bronze, the fuse element may be inserted in the straight intermediate portion of the bridge element and secured in place as by means of soldering. In the event of an overload or short circuit, the fuse element 104 simply melts and interrupts the connection between the contacts 40.

I claim:

1. A multi-conductor electrical connector comprising the combination of a first member, a contact holder on said first member, a plurality of contacts in said contact holder, a second member, a contact holder on said second member, a plurality of contacts in said second member contact holder, a bridge holder attached to one of said members and adapted to receive the contacts of both said contact holders, a plurality of resilient bridge elements captive-mounted within said bridge holder, said bridge elements being disposed in electrical contact with respective aligned pairs of said contacts upon assembly of said first and second members together, the contacts of both said contact holders each comprising an inner sleeve adapted to slidably receive the conductor wire, said sleeve having inner and outer ends including an outwardly flared mouth portion at its inner end, a flange intermediate said ends and longitudinally extending slots between said outer end and said flange, an outer cap adapted to be press fit on the slotted portion of said sleeve, said cap including an enlarged portion with an axial bore theretnrough for receiving said slotted sleeve and the contact extending outwardly from said enlarged portion.

2. In a multi-conductor electrical connector having first and second members with opposed sets of contacts thereon, a bridge assembly comprising, in combination, a first disk of nonconductive material, a second disk of non-conductive material secured to said first disk, means defining a pair of aligned cavities in said disks, means defining contact apertures in said disks communicating with said cavties, a resilient bridge element captive-mounted within said cavities, said element having generally V-shaped end portions and a relatively straight intermediate portion the apexes of said V-shaped end portions being urged against the contacts for effecting wiping electrical contact therebetween upon assembly of said members, means for securing said first and second disks to one another, and means for releasably securing said bridge assembly to one of said first and second members.

3. In a multi-conductor electrical connector having first and second members with opposed sets of contacts thereon, a bridge assembly comprising, in combination, a bridge holder including a pair of spaced non-conductive material elements adapted to receive said opposed sets of contacts, a plurality of resilient bridge elements having generally V-shaped end portions and a relatively straight intermediate portion captive mounted within said bridge holder, and means for subjecting said bridge holder to compression upon attach-ment of said first and second members together, so that the apexes of said V-shaped end portions of said bridge elements are forced into positive electrical contact with a pair of said opposed contacts.

4. A multi-conductor electrical connector comprising, in combination, a first member, a plurality of contacts on said first member, a second member, a plurality of opposed contacts on said second member, a bridge holder adapted to receive the contacts of both said members, said bridge holder including two axially spaced disk members wit-h a biasing means interposed therebetween tending to spread them apart, a plurality of bridge elements captivemounted within said bridge holder, and means for bringing said first member into engagement with said second member and for compressing said disk members together as an incident to such engagement, whereby said bridge elements become forced into electrical contact with respective aligned pairs of said contacts upon engagement of said first and second members together.

5. A multi-conductor electrical connector comprising, in combination, a first member, a plurality of contacts on said first member, a second member, a plurality of op posed contacts on said second member, a bridge holder including axially spaced disk members adapted to receive the contacts of said first and second members, a plurality of resilient bridge elements captive-mounted within said bridge holder, and means for urging said first member into engagement with said second member and for compressing said disk members together as an incident to such engagement, whereby said bridge elements become forced into electrical contact with respective aligned pairs of said contacts upon, assembly of said first and second members together. i

6. A multi-conductor electrical connector comprising, in combination, a first member, a plurality of contacts on said first member, a second member, a plurality of contacts on said second member, a bridge holder interposed between said members adapted to receive respective aligned pairs of said contacts upon assembly of said first and second members together, a plurality of resilient bridge elements captive-mounted within said bridge holder, said bridge elements including means for effecting wiping electrical contact between said opposed contacts as an incident to securing said first and second members together, means for releasably securing said bridge holder to one of said first and second members, and means associated with each of said first and second members for receiving said securing means so that said bridge holder can be secured to either one of said members.

7. A multi-conductor electrical connector as claimed in claim 6 wherein said resilient bridge elements have generally V-shaped end portions and a relatively straight intermediate portion.

8. A multi-con ductor electrical connector as claimed in claim 6 wherein said resilient bridge elements include generally W-shaped end portions.

9. A multi-conductor electrical connector as claimed in claim 6 wherein said bridge elements include a fuse element interposed between the ends thereof.

10. A multi-conductor electrical connector comprising, in combination, first and second interfitting members, means for attaching said first member to said second member, a plurality of contacts on said first and second members, a bridge holder including a pair of spaced non-conductive material elements adapted to receive the contacts of both said members, a plurality of resilient bridge elements captive-mounted within said bridge holder and said disk members being compressed so that said bridge elements become forced into electrical contact with respective aligned pairs of said contacts when said securing means attaches said first and second members together.

11. A multi-conductor electrical connector comprising, in combination, a first member, a plurality of contacts on said first member, a second member, a plurality of contacts on said second member, a bridge holder interposed between said members adapted to receive respective aligned pairs of said contacts upon assembly of said first and second members together, a plurality of bridge elements within said bridge holder, means for releasably securing said bridge holder to one of said first and second members, and means associated with each of said first and second members for receiving said securing means so that said bridge holder can be secured to either one of said members.

References Cited UNITED STATES PATENTS 2,147,239 2/1939 Buchanan 339-273 2,225,718 12/1940 Sheppley et al. 339-196 X 2,563,561 8/1951 Stanley 339-159 2,806,214 9/1957 Forney 339-276 2,866,957 12/1958 Raypholtz 339-205 X 2,954,542 9/1960 Wales 339-89 X 2,959,766 11/1960 Jacobsen 339-273 3,149,897 9/1964 Martineck 339-176 MARVIN A. CHAMPION, Primary Examiner.

W. DONALD MILLER, Examiner.

J. H. McGLYNN, Assistant Examiner, 

1. A MULTI-CONDUCTOR ELECTRICAL COMPRISISNG THE COMBINATION OF A FIRST MEMBER, A CONTACT HOLDER ON SAID FIRST MEMBER, A PLURALITY OF CONTACTS IN SAID CONTACT HOLDER, A SECOND MEMBER, A CONTACT HOLDER ON SAID SECOND MEMBER, A PLURALITY OF CONTACTS IN SAID SECOND MEMBER CONTACT HOLDER, A BRIDGE HOLDER ATTACHED TO ONE OF SAID MEMBERS AND ADAPTED TO RECEIVE THE CONTACTS OF BOTH SAID CONTACT HOLDERS, A PLURALITY OF RESILIENT BRIDGE ELEMENTS CAPTIVE-MOUNTED WITHIN SAID BRIDGE BOLDER, SAID BRIDGE ELEMENTS BEING DISPOSED IN ELECTRICAL CONTACT WITH RESPECTIVE ALIGNED PAIRS OF SAID CONTACTS UPON ASSEMBLY OF SAID FIRST AND SECOND MEMBERS TOGETHER, THE CONTACTS OF BOTH SAID CONTACT HOLDERS EACH COMPRISING AN INNER SLEEVE ADAPTED TO SLIDABLY RECEIVE THE CONDUCTOR WIRE, SAID SLEEVE HAVING INNER AND OUTER ENDS, INCLUDING AN OUTWARDLY FLARED MOUTH PORTION AT ITS INNER END, A FLANGE INTERMEDIATE SAID ENDS AND LONGTUDINALLY EXTENDING SLOTS BETWEEN SAID OUTER END AND SAID FLANGE, AN OUTER CAP ADAPTED TO BE PRESS FIT ON THE SLOTTED PORTION OF SAID SLEEVE, SAID CAP INCLUDING AN ENLARGED PORTION WITH AN AXIAL BORE THEREBETWEEN FOR RECEIVING SAID SLOTTED SLEEVE AND THE CONTACT EXTENDING OUTWARDLY FROM SAID ENLARGED PORTION. 